First post, by Pantheon
Hi, I'm new here!
I thought I might share with you a little fun I had last night.
As many know the YM262 outputs digital data which is then converted into analog by the YAC512.
I hooked up a logic analyzer to the YM262 and captured the output data stream on its way to the YAC512. I then wrote a C program to parse the output data and convert it into a PCM format. The output of this method should be the cleanest possible sound.
While the YM262 outputs 16bit sound samples, the YAC512 itself converts the sound into a floating point format (10bit mantissa, 3bit exponent) which will reduce the sound quality. Then various output amplifier and filtering stages will farther colour the sound, and introduce a noise floor.
The quantization, colouring and noise floor might be subjectively part of the OPL3 sound, but its interesting to hear it in the cleanest possible form.
I have uploaded some pics and a sound sample from Monkey Island 1.
My "next step" is to have my FPGA decode the data stream and output it to a high quality I2S DAC, so I can listen to it in real time.
Audio sample file, forrest.flac:
https://drive.google.com/open?id=13KdTo0mgD25 … 7b3bWknXtacP-iY